Stoker



Jan. 7, 1936. 7 L: R, T W 2,026,805

STOKER Filed Sept. 12, 1951 2 Sheets-Sheet l Luz c7 8 Stowe,f/vl/f/vrola 75 (961% M v ATTORNEYS Jan. 7, 1936. L R TOWE 2,026,805

STOKER Filed Sept. 12, 193l 2 Sheets-Sheet 2 INVENTOR. L 0 a? 711 52 0we A TTORNEYS.

Patented Jan. 7, 1936 PATENT OFFICE STOKER Loyd R. Stowe, ShakerHeights, Ohio Application September 12,1931, Serial No. 562,436

2 Claims.

The present invention has for its object the provision of certainadvantageous improvements in the construction of a mechanically operatedfurnace, or as more commonly termed, stoker.

Briefly outlined, the novel improvements embodying the principle of myinvention reside in the provision of a plurality of multipart gratebars, all lying in the same plane, said bars being alternately fixed andreciprocable. My construction also contemplates the provision of airpassages of progressively varying areas throughout the length of thefuel bed. Furthermore, such a multipart construction of the grate barsprevents warpage or misalignment. Another advantage of this assembly ofsmall parts is that the cost of replacement and maintenance is greatlyreduced inasmuch as in case of burning out or damaging a portion of agrate bar, it is necessary to remove and replace only the injured oraffected part without discarding the remaining undamaged portion of thegrate bar assembly as would be the case in a one-piece or unitconstruction. I

A further advantage is that by virtue of the fact that the grate surfaceas composed of the stationary and reciprocable grate bar elements,

which are disposed in a single plane, there is presented a uniform andunbroken plane surface for the perfect forwarding of the fuel from thefeeding end to the discharge end. Furthermore, inasmuch as it is foundpractical to construct the reciprocating bars of greater width,

any disturbing action of the fuel bed which is necessarily incident to anarrow bar construction is eliminated.

Objects and advantages additional to those above enumerated shall becomeapparent as the description proceeds. To the accomplishment of theforegoing and related ends, said invention then, consists of the meanshereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detailcertain mechanism embodying the invention, such disclosed meansconstituting, however, but one of various 'mechanical forms in which theprinciple of the invention may be used.

In said annexed drawings:

Fig. 1 is a side elevation illustrative of a stoker constructionembodying the principle of my invention; Fig. 2 is an enlarged plan viewof a portion of the grate surface; and Fig. 3 is an enlarged sectionalview takensubstantially upon the line 3-3 of Fig. 2.

Referring more particularly to the drawings, in Fig. 1 I have shown acombustion chamber having the front wall I, the back or bridge wall -2,and the ash pit 3. The stoker frame 4.0ccupies the space below thecombustion chamber, 5 and is suitably supported at both ends by thevertical beams 5 and 6. The stoker frame carries upon its upper portionthe grate bar elements, indicated generally by the numeral I, upon whichthe fuel bed is intended to be posi- 10 tioned. The fuel is fed to theupper end of the grate surface I by means of the reciprocable action ofthe pusher plate 8, which is actuated by a motor'lll connected to a wormreduction unit II, which in turn is connected to the large gear l2mounted upon the shaft l3. The shaft l3 extends across the front of thestoker and on its opposite end carries the crank arm M connected to theslotted lever arm I5 which in turn actuates a plurality of pinions l6which engage 20 with the gear racks H on the under side of the pusherplate 8. The lever arm l5 has a longitudinal slot l8 in which the end ofthe pitman arm l9 may be adjustably positioned by suitable means, withthe result that the degree of recip- 25 rocable travel of the pusherplate 8 can be adjusted or varied.

The pusher plate has on its under side a plurality of downwardlyextending lugs 20 to which are bolted or otherwise secured the sections2| 30 of the reciprocating grate bars. As shown in Fig. 2,. two of thesections 2| are bolted together laterally in order to compose a gratebar element. Stationary grate bars composed of the sections 22 are thenalternately placed between the re- 35 ciprocable grate bars, the latterbeing spaced apart to permit this arrangement. The sections 2| and 22 ofeach bar are positioned in such a longitudinal contact that the entiregrate bar element is essentially rigid and non-flexible This latterstructural expedient may be accomplished by means of squaring thecontacting ends of the sections as shown in Fig. 1, or by any otherequivalent design, such as interfitting notches on the ends of thesections.

These grate bar elements are supported by means of several transversechannel bars 23 carried by the stoker frame 4. In order to provide ameans for guiding the travel of the reciprocating grate bars, the guides24, which are mounted against the cross channel bars 23, are held inaligned position by means of a rod 26 extending the length of the stokerframe. In order to properly longitudinally space the guides 24, theremay be placed between the guidesand 56 the adjacent channel bars aplurality of pipe sec tions 21. As best shown in Fig. 3, the guides 24have the upwardly projecting lugs 28 and 29 in order to prevent lateraldisplacement of the reciprocating sections 2!.

Adjacent sections 2| have the complementary lateral bosses 30 and 3!which are adapted to bear against each other along a line 32. Suitablebolts 33 and nuts 34 may be provided in order to laterally secure thesections 2! together. The upper flanges 35 of the sections 2| are madeprogressively wider from the lower end of the stoker to the upper endwith the result that there will occur a series of tapered air passageslongitudinally extending up the face of the grate surface. One advantageof such a construction is that the air admitted to the fuel bed may beappropriately varied for successive stages of combustion down thestoker. Another advantage of providing reduced air passages at the upperend of the stoker is that the amount of sifting before the fuel bed hashad an opportunity to thoroughly coke, is reduced. Directing attentionto Fig. 1, the stationary grate bars are secured at the lowerend of thestoker by means of downwardly extending lugs 36 on the last sections. Ahook bolt 31 connects the lugs 36 to the bracket 38 on the transversechannel beam 39. It will thus be seen that the stationary grate barelements are free to expand upward and lengthwise of the stoker frame;and that the reciprocating grate bar elements 2| being secured to thepusher plate 8 are free to expand lengthwise and downward of the stokerframe.

The retarding or dump plate 40 may be pivotally secured at the point 4|on the lower end of the stoker frame. The angular inclination of thedump plate 40 may be appropriately varied in any suitable manner, as forexample, by means of the set screw 42. along the ash pit 3 in order tofacilitate remova of ashes therefrom.

The retarding or dump plate 40 serves the function of regulating therate of movement and the depth of the fuel bed on the grate bars, whichwill be proportionate to the resisting or retarding action of the plate40. Furthermore different A door 43 may be positioned types of fuel willrequire different degrees of retardation, which varies inversely as theash content of the particular fuel. The variation in angular inclinationof the plate 40 serves as a convenient means for adjustment toaccommodate various types and grades of fuel.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a stoker, the combination of an inclined 1 spect to each other, aplurality of stationary L..-

grate bars similarly composed of sectional elements, said stationarybars being alternately disposed with respect to said movable bars, andmeans for slidably sup-porting said movable bars comprising memberssecured to said frame and positioned transversely with respect to saidmovable bars, and guide members mounted against said transverse membersand bearing against said movable bars.

2; In a stoker, the combination of an inclined y frame, a plurality ofmovable grate bars mounted upon said frame, said grate bars beingcomposed of small sectional elements rigidly secured together bothlaterally and longitudinally with re spect to each other, a plurality ofstationary grate bars similarly composed of sectional elements, saidstationary bars being alternately disposed with respect to said movablebars, the upper surfaces of all of said grate bars being disposed in acommon plane, and means for slidably 4 supporting said movable barscomprising members secured to said frame and positioned transverselywith respect to said movable bars, and guide members mounted againstsaid transverse members and bearing against said movable bars. 4

LOYD R. STOWE.

